convert single to double acting ram?

[Cord]

I have a log splitter project that I was working on some time ago and set aside for the lack of a ram. The splitter has a multi-way head and I'm just not comfortable with a 5" ram. A 5" might work, but I'm not certain it will. So I've been searching for a 6" ram. It'll be slower than I want, but it'll have the power I may need. I recently found one for a good price, but it's off a forklift so it's single acting. Can the second port be added to a single acting ram thus converting it to a double acting ram? When the port is missing, how is the air typically vented? Because this is a splitter application, the ram won't see much pressure on the return stroke, just enough to activate the detent.

 

[Villengineer]

First, a 5" bore cylinder would produce almost 10 ton of force at 1000 psi. That's quite a bit of force.
On to the cylinder question. The only definitive answer I could give is that it's probably less time consuming and cheaper to just find a double acting. The ease in converting a single to double depends entirely on the construction of the actual cylinder involved. Single actings can be built with or without pistons and that would be the first determining factor - ie no piston, no double acting. If the cylinder does in fact have a piston, the seal design then becomes an issue. If the retainer isn't set up for more than a wiper, you looking at altering it at the least and may have to make a custom piece. $$$

 

[Egon]

Don't think I'd try and make a conversion as per reasons already stated.

Have you considered attaching a spring or smaller inexpensive ram for the return?

Egon

 

[gizmo]

I have a splitter with a 4" cylinder running on 2200psi and it will shear a 10" log in half sideways. I have never had it stall while splitting a log. What's with the need for a 6" cylinder?

I agree with the above about converting a single acting cylinder.

 

[bobodu]

With the right pump a 4" works just fine.
I have a sneaking suspicion that a forklift ran is a cup seal affair and these aren't really meant for that type of pressure.Forklifts generally have chain over pulleys that change the mechanical advantage.
My neighbor has a 5" ram on his splitter that he runs off an Oliver 1850....no log has ever won.

 

[MikeD74T]

Depending on the design of the end cap & the material it's made of, you could possibly drill & tap a hole to accept a second hydraulic line. how about some pics? What is the shaft diameter of the piston?

 

[Deerlope]

Before going to that 6" you better do your homework cause you can bend an awful lot of steel with a 5". What is the max pressure your pump will produce? What kind of wood are you spliting?

 

[Cord]

I don't have the ram yet, but I found a junk yard that had a bunch of old forklifts. Thought maybe one of their rams might work for me.

The splitter has a 7 way head on it. Not the traditional two way. You feed the log in and it cleaves it in half. The one half is then cleaved 6 more times. All of this is done in one pass. I was planning on using a 28gpm two stage pump. The pump is capable of 3,000psi sustained. A 6" ram won't give the inches per minute I'd like, but with the splitter design it will only take two pushes to finish a log. The splitter that I designed this off of used a 5" ram. I figured that my head design wasn't as efficient as theirs. My head is also welded on where as their design allowed the head to be removed and replaced with a two way wedge for a really curly piece of wood. For these reasons I was thinking that I should go with a 6". The frame for the splitter is a 8"x12"x5/16" rectangular tube.

 

[dfkrug]

Yes, you can convert them. I have done it. Some of the 3-pt concrete mixers come with crappy single-acting cylinders. If your SA cylinder is extension only, you may not have good rod seals cuz the piston seal does all the sealing you need. I found my SA cylinder worked fine with only welding on an adapter and making sure the air bleed on the retraction side was sealed.